\begin{tikzpicture}
    \draw (0, 3) ellipse [x radius=2, y radius=1] node[below=1.2] {正有理数集合};
    \draw (5, 3) ellipse [x radius=2, y radius=1] node[below=1.2] {负有理数集合};
    \draw (0, 0) ellipse [x radius=2, y radius=1] node[below=1.2] {正无理数集合};
    \draw (5, 0) ellipse [x radius=2, y radius=1] node[below=1.2] {负无理数集合};
\end{tikzpicture}
